updated 10:20 pm EDT, Mon June 7, 2010
Public release scheduled for end of June
Apple has released the iOS 4 gold master to developers, several weeks ahead of the formal iPhone 4 introduction. The operating system, formerly referred to as the iPhone OS, will bring a variety of new features to the company's range of mobile devices.
The update will allow users to take advantage of multitasking, a unified inbox, e-mail threading, and folders for app organization. iBooks and iMovie will also arrive on the iPhone platform, along with Bing as a search option.
The formal iOS release is scheduled for June 21, with downloads to be available for any iPhone and iPod touch except for first-generation models.